The present invention relates to an improved disc brake rotor for automotive applications which achieves the same structural rigidity of rotors of conventional construction with a substantially reduced weight, together with improved cooling characteristics.
While useful in other applications, the present invention is disclosed as being applied to disc brake rotors of the type used in automotive vehicles. The standard brake rotor presently in commercial use for this purpose is constructed as a one piece casting having a hub integral with a first annular plate like braking member. A second annular plate like braking member is integrally joined to the first braking member by a plurality of fins which extend between the two opposed faces of the braking members to support the second braking member in axially spaced coaxial relationship to the first braking member. The fins are spaced from each other to provide for air flow between the opposed faces of the braking members to dissipate the frictional heat generated by application of the vehicle brakes.
In the presently employed standard configuration, the fins which join the two braking members to each other lie in general planes which extend radially from the rotor axis with the radial dimension of the individual fins substantially exceeding the thickness of the fins circumferentially of the rotor axis.
The number, shape and size of the fins employed to join the two braking members to each other must be such as to provide adequate structural strength to transmit braking forces applied to the rib supported braking member to the hub supported braking member while at the same time leaving enough open space between the ribs to accommodate sufficient air flow between the two members to provide adequate cooling. The industry standard radial fin brake rotor has been used for many years, and its design details and techniques for manufacturing the rotor have been exhaustively refined. While many alternative fin arrangements have been proposed, few, if any, have enjoyed any substantial commercial success, typically because any improved performance achieved by alternative designs has been outweighed by increased manufacturing costs.
The present invention is directed to a brake rotor having fins dimensioned and configured in a manner such that less than half of the material required to form the fins of a standard radial fin rotor of comparable dimensions and strength need be employed. In addition to reducing the overall material cost, a substantial reduction in weight without a corresponding reduction in structural rigidity is achieved. The new rib configuration and arrangement can be manufactured by the same manufacturing techniques employed to manufacture radial fin rotors, and the improved fin arrangement also achieves better cooling air flow through the rotor than is obtained with the standard radial fin arrangement.